Rock Identifier
Basalt with Quartz/Calcite Veins (Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions) — igneous
igneous

Basalt with Quartz/Calcite Veins

Basalt (Aphanitic Mafic Volcanic Rock) with Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3) inclusions

Hardness: 5-6 (Basalt host), 7 (if Quartz veins) or 3 (if Calcite veins). Color: Dark gray/black matrix with white decorative veining. Luster: Dull/earthy for the base rock, vitreous for the veins. Structure: Fine-grained/aphanitic with secondary mineral infill.

Color
Dark gray/black matrix with white decorative veining
Luster
Dull/earthy for the base rock, vitreous for the veins
Identified More igneous →

Identify your own rocks.

Get a report just like this from any photo, free.

App StoreGoogle Play

Physical properties

Hardness: 5-6 (Basalt host), 7 (if Quartz veins) or 3 (if Calcite veins). Color: Dark gray/black matrix with white decorative veining. Luster: Dull/earthy for the base rock, vitreous for the veins. Structure: Fine-grained/aphanitic with secondary mineral infill.

Formation & geological history

Formed from the rapid cooling of magnesium-rich and iron-rich lava at or near the Earth's surface. The white veins formed later when hydrothermal fluids filled cooling cracks, precipitating minerals over thousands of years.

Uses & applications

Commonly used in construction as crushed stone for road base or concrete aggregate. High-quality rounded river stones are popular for landscaping, decorative garden accents, and aquarium decor.

Geological facts

Basalt is the most common rock type in the Earth's crust and makes up most of the ocean floor. The white 'veins' are often referred to by collectors as 'heart strings' or 'wishing lines' when they encircle the whole stone.

Field identification & locations

Identify in the field by its heavy weight (high density), dark color, and the presence of distinct crystalline white bands that do not scratch easily (if quartz). Often found in glacial till, riverbeds, and coastal regions.

More like this

Other igneous specimens

Blue Apatite (Fluorapatite (Ca5(PO4)3F)) — mineral

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral
Dark Igneous Rock (Likely Basalt or Diabase) (Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.) — Igneous

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous
Magnetite (Iron(II,III) oxide (Fe3O4)) — mineral

Magnetite

Iron(II,III) oxide (Fe3O4)

mineral
Sodalite (Sodalite - Na8(Al6Si6O24)Cl2) — mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral
Blue Apatite (Apatite (Group), Ca5(PO4)3(F,Cl,OH)) — mineral

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral
Magnetite (Magnetite (Fe3O4)) — mineral

Magnetite

Magnetite (Fe3O4)

mineral